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<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    let num1 = 10
    let num2 = num1
    num2 = 20
    console.log(num1) // 结果是？


    let obj1 = {
      age: 18
    }
    let obj2 = obj1
    // 修改属性
    obj2.age = 20
    console.log(obj1.age)
  </script>
</body>

</html>